# Homework Help: Application of Laplace problem

1. Jun 16, 2012

### NewtonianAlch

1. The problem statement, all variables and given/known data
http://img836.imageshack.us/img836/9994/27794040.jpg [Broken]

3. The attempt at a solution

Here is the circuit I re-drew:
http://img403.imageshack.us/img403/6752/dsc0048ga.jpg [Broken]

Working out:

http://img857.imageshack.us/img857/5633/dsc0049mo.jpg [Broken]

I got the denominator correct, but my numerator isn't. Which means I got something wrong with the sources in the circuit, but I'm not sure where.

Last edited by a moderator: May 6, 2017
2. Jun 16, 2012

### rude man

It's hard to read your paper. I can only offer you what I do in cases like this where initial conditions exist:

1. Change the Laplace equations to differential equations, ignoring the initial conditions.

2. Change the differential equations back to Laplace domain, using the Laplace transform rules for including initial conditions, e.g.
if F(s) = L{f(t)} then L{f'(t)} = sF(s) - f(0+) etc.

3. Then do the inverse transforms term-by-term.

This is probably equivalent to what you're trying to do, I can't tell.

3. Jun 17, 2012

Nvm, solved.